Universal quantum computation in decoherence-free subspaces with hot trapped-ions

TL;DR

This paper proposes a method for universal quantum computation using decoherence-free subspaces in trapped ions, effectively mitigating collective dephasing and enabling robust quantum gate implementation.

Contribution

It introduces a universal set of quantum gates within decoherence-free subspaces for trapped ions, including explicit Hamiltonian parametrizations that prevent leaving the protected subspace.

Findings

Elimination of collective dephasing as a major decoherence source.

Explicit two-body Hamiltonian parametrization for protected gates.

Feasibility of implementing universal quantum gates in trapped-ion systems.

Abstract

We consider interactions that generate a universal set of quantum gates on logical qubits encoded in a collective-dephasing-free subspace, and discuss their implementations with trapped ions. This allows for the removal of the by-far largest source of decoherence in current trapped-ion experiments, collective dephasing. In addition, an explicit parametrization of all two-body Hamiltonians able to generate such gates without the system's state ever exiting the protected subspace is provided.